1. Field of the Invention
This invention relates to a dynamically tuned gyro and more particularly to a dynamically tuned gyro in which various components of the gyro such as the end cap having a hysteresis ring, the stator and the gyro rotor can be assembled together by stacking them one upon the other only from the upper side of the rotary shaft.
2. Related Art Statement
As to the conventionally employed dynamically tuned gyros, there are so far proposed a variety of constructions, as typified by the construction shown in FIG. 4 of my Japanese laid open patent application 62-162618, published 16 October 1987 , such construction also being shown in FIG. 1 of the accompanying drawings.
Referring now to FIG. 1, the numeral 1 denotes a casing having the shape in cross-section of an inverted letter U and on the inner wall 1a of the casing 1 there is fitted a frame 3 having a pair of ball bearings 2 at the central portion thereof.
A stator 4a having a stator winding 4 is stationarily provided at the inner wall 3a of the frame 3 and a rotor shaft 5 is mounted for rotation on an inner ring 2a of each of the bearings 2.
The frame 3 is secured to an outer ring 2b of each of the bearings 2. A substantially annular hysteresis ring 7 is provided at the outer periphery of a generally U-shaped end ring 6 secured to the lower end 5b of the rotary shaft 5 and to the inner ring 2a. The end cap 6 and the hysteresis ring 7 constitute a motor rotor 8, while the stator 4a and the motor rotor 8 constitute the spin motor 9.
At the upper part of the rotary shaft 5 a gyro rotor 13 is mounted through the medium of a gimbal 10 and a spring member 11. The gyro rotor 13 is a ring-like member having generally the shape of a letter U. On the inner wall of the gyro rotor 13 is secured a ring magnet 14.
On the lower end of the gyro rotor 13 a sensor ring 15 is provided and a sensor coil 16 is upstandingly mounted on the frame 3 in a facing relation to the sensor ring 15.
On the upper surface of the frame 3 a torque coil 17 is upstandingly mounted, uppermost part of which is located inside of the gyro rotor 13 in a facing relation to the ring magnet 14.
The above described dynamically tuned gyro operates in the following manner.
When the spin motor 9 is actuated in the state of FIG. 1, the rotary shaft 5 is revolved at a high speed for driving the gyro rotor 13 into rotation at high speed.
When a tilt is caused in the gyro rotor 13, this tilted state is sensed by the sensor coil 16, a corresponding control current is impressed across the torque coil 17, and a force of a magnitude proportionate to the product of the magnetic flux through the ring magnet 14 and the control current in the torque coil 17 acts on the gyro rotor 13 for controlling the posture of the gyro rotor 13 in a well-known manner.
In the above described dynamically tuned gyro, the following problems were presented.
Since the motor rotor 8 for the spin motor must be mounted below the lower bearing 2 of the rotary shaft 5, it is difficult to resort to an assembling method of stacking the components from the lower position component on, and the frame 3 has to be supported by, a jig, not shown.
As a result, the efficiency of the assembling operation cannot be improved since the motor rotor 8 which is a component of the spin motor must be attached to the rotary shaft 5 with the frame in the inverted position and the frame must be again brought to its normal position for assembling the gyro rotor. It is very difficult to assemble said gyro rotor.